Hempel explored Facebook’s turnaround in the mobile sector, from its ill-advised attempt to ignore Android and iOS and build an application that would work on all devices — “It’s probably one of the biggest mistakes we’ve ever made,” Zuckerberg said — to its introduction of Home, a Facebook-dominated overlay for the Android platform.

Hempel wrote on Home:

Given Facebook’s engineering prowess, it is possible that Home or other Home-like software could expand to the point where the technology totally consumes a device so that it isn’t even recognizable as a Google-powered phone — all thanks to Google’s open-source largesse. Think of Facebook here as potentially like a strangler fig, a type of epiphyte that gloms onto another plant or tree, growing around and over it, competing with its host for nutrients. (Google, which wasn’t involved in the development of Facebook Home, declined to comment on the product, although Zuckerberg confirms that the search giant saw it prior to launch.)

Easy Facebook access is particularly important in parts of the developing world, where the service’s next billion members are just beginning to go online. Data is prohibitively expensive in this part of the world, and Facebook has struck deals with some carriers in which customers who buy the Home-enabled phones will have access to free data for a period — Facebook pays — and will be able to surf the Web, or at least Facebook’s Web. Sure, those customers may be buying an HTC or a Samsung phone, and it may be powered by Android, but their first experience of the web will be on Facebook, through Facebook Home.

If the company is successful with Home, that may also have implications for Apple. Apple is the company that invented the design for the modern smartphone, after all — a window populated by apps. So far, no one has been able to disrupt this design interface, though many companies, including Microsoft, have tried. Most recently BlackBerry’s z10 introduced a new and intuitive approach to navigating the mobile Web, but users have yet to embrace it. By attempting to move the design focus away from the names of the services we use on our phones and toward the images of the people to whom we connect, Facebook is introducing a new way to navigate the platform. “We’d love to be able to offer this on iPhone, too,” Zuckerberg says. “We just can’t today.”

And though Facebook Home makes its debut without ads, it’s an easy leap to imagine how valuable a News Feed ad on Facebook’s home screen may be in the future. Says Zuckerberg: “Most of the ads are just sponsored content. We don’t have any yet, but at some point we will.”

There’s always the chance that even Facebook lovers will feel besieged by too much Facebook, or that consumers have already been trained to favor apps over the deeper integration that Zuckerberg is peddling. Or it just might be that in order to be a great tech company in the 21st century, Facebook needs to overhaul itself yet again and figure out a way to make a device and develop its own operating system — or both. Luckily for Zuckerberg, he’s already been through one Facebook reboot, and he has shown he can make the tough calls.